A sound source localizing technique for an outdoor intelligent CCTV camera is to sense an important sound event such as a scream of a human, a sound of collision of vehicles, or the like, turns the CCTV camera to a location where the corresponding sound source is generated to intensively monitor the event, and informs the monitoring result to a relevant security department so that surrounding situations may be more safely protected.
However, an outdoor environment has various and random noise, different from an indoor environment. Such noise representatively includes motorcycle noise, engine sound of vehicles, wind sound or the like, and a false alarm (or, misrecognition) frequently happens due to such noise. In case of wind noise, it is difficult to find regular patterns, in comparison to other noise (for example, vehicle or motorcycle noise) since the wind strength and direction varies randomly due to various factors. An existing sound direction monitoring system generally ensures good operation only in a silent indoor environment. If there is noise, the existing sound direction monitoring system may operate satisfactorily just in an environment having noise which is very low or very stable. In other words, there is urgently needed a sound direction monitoring technique which may effectively respond to wind noise which is always present in an outdoor environment.